Submillimetre observations of WISE-selected high-redshift, luminous, dusty galaxies
We present SCUBA-2 (Submillimetre Common-User Bolometer Array) 850 μm submillimetre (submm) observations of the fields of 10 dusty, luminous galaxies at z ∼ 1.7–4.6, detected at 12 and/or 22 μm by the Wide-field Infrared Survey Explorer (WISE) all-sky survey, but faint or undetected at 3.4 and 4.6 μm; dubbed hot, dust-obscured galaxies (Hot DOGs). The six detected targets all have total infrared luminosities greater than 10^(13) L_⊙, with one greater than 10^(14) L_⊙. Their spectral energy distributions (SEDs) are very blue from mid-infrared to submm wavelengths and not well fitted by standard active galactic nuclei (AGN) SED templates, without adding extra dust extinction to fit the WISE 3.4 and 4.6 μm data. The SCUBA-2 850 μm observations confirm that the Hot DOGs have less cold and/or more warm dust emission than standard AGN templates, and limit an underlying extended spiral or ULIRG-type galaxy to contribute less than about 2 or 55 per cent of the typical total Hot DOG IR luminosity, respectively. The two most distant and luminous targets have similar observed submm to mid-infrared ratios to the rest, and thus appear to have even hotter SEDs. The number of serendipitous submm galaxies detected in the 1.5-arcmin-radius SCUBA-2 850 μm maps indicates there is a significant overdensity of serendipitous sources around Hot DOGs. These submm observations confirm that the WISE-selected ultraluminous galaxies have very blue mid-infrared to submm SEDs, suggesting that they contain very powerful AGN, and are apparently located in unusual arcmin-scale overdensities of very luminous dusty galaxies.
Additional Information© 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2014 June 9. Received 2014 June 2; in original form 2014 January 24. First published online July 9, 2014. The authors would like to thank the anonymous referee for his/her comments and suggestions, which have greatly improved this paper. SFJ gratefully acknowledges support from the University of Leicester Physics & Astronomy Department. RJA was supported by Gemini-CONICYT grant number 32120009. This publication makes use of data products from the WISE, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. The James Clerk Maxwell Telescope is operated by the Joint Astronomy Centre on behalf of the Science and Technology Facilities Council of the United Kingdom, the Netherlands Organization for Scientific Research, and the National Research Council of Canada. Additional funds for the construction of SCUBA-2 were provided by the Canada Foundation for Innovation. The project ID under which the data were obtained was M12AU010.
Published - MNRAS-2014-Jones-146-57.pdf